The closing year of the '50s witnessed the retirement of Bridge founder Joseph A. Bower as chairman, after 30 years at the helm of the Bridge he built. In handing over the chairmanship to son Robert, he remained a director. And change continued.

Throughout the decade, further physical developments took place: Ammex Duty Free store opened on the U.S. plaza (1963); the office buildings were renovated to provide more space for customs brokers (1964); the Canada Customs office was doubled in size (1966); negotiations that would drag on for a decade were begun with the U.S. Government to enlarge the U.S. plaza (1968); and a large-scale rehabilitation program was begun in 1969, the Ambassador Bridge's 40th anniversary, part of which saw the complete rewiring of the Bridge and the installation of new mercury vapor lamps and new electrical transformers.

In 1970, $850,000 was spent over a period of eight months in repairing the Bridge's roadway. The U.S. approach roadway deck was rehabilitated by replacing some base concrete and installing a complete asphalt overlay, the first such replacement in the Bridge's 40 years.

The original granite blocks, which had been embedded in sand to provide traction on the U.S. side's five percent grade, were replaced with the asphalt paving. The blocks were given to the Windsor Parks & Recreation Department, and now grace many of the pathways in Windsor parks.

A rehabilitation of the Canadian roadway approach was completed in 1972, and new Canadian entrances and exits were completed to accommodate the new four-lane highway leading into the Bridge. A new U.S. toll plaza - with eight booths, islands and canopies and two 70 - foot, 150,000 - pound truck scales - was constructed in 1972, with comparable facilities also added on the Canadian side in 1973. 1973 also saw an extensive painting program, the paving of both terminals and construction of a new Ammex distribution and warehouse building on the U.S. terminal. The tower signs were also replaced that year at a cost of $33,000. Originally erected in about 1933, and replaced for the first time in 1952, each tower sign displays the words, "Ambassador Bridge", in six-foot-high letters.

New secondary car inspection facilities were completed for Canada Customs on the Canadian terminal at a cost of $360,000 during 1975, and the primary inspection area was demolished and replaced with new, enlarged facilities at a cost of $325,000 the next year. Following an in-depth inspection of the Bridge structure, a special preventive maintenance program was inaugurated in 1976. The following year, the main cable band bolts were replaced for the first time as part of the program whose total cost approached $650,000. In 1974, a new retail sales store for Ammex was built on the U.S. terminal. In 1978, plans were made to install a $300,000 computerized toll system. But the president and general manager's plans for expanding the Detroit plaza through adding a new terminal building for U.S. Customs truck clearance adjacent to the plaza were stalled through the entire decade by the lack of progress in negotiations with the U.S. Government's General Services Administration.

The congestion on the U.S. plaza continued to mount as the decade progressed. By mid-decade, the Greater Detroit Chamber of Commerce and local municipal and county officials had entered into the negotiations to try to untangle the bureaucratic red tape impeding the expansion. In early 1977, the Bridge company purchased a $1.2 million, 40-door terminal building from a neighboring trucking company with the intent of leasing it to GSA for use by U.S. Customs for truck clearance. This offer was refused, and the Bridge company then offered to sell the facility to GSA at cost.

The terminal building still sits vacant two years later, waiting for GSA, which prefers to purchase on its own terms. The Bridge company offered in May 1979 to provide it without cost to the U.S. Government. GSA has also refused that offer. In contrast, truck examination on the Canadian side has run smoothly for many years, and was further improved in 1973 when its truck examination area was segregated from the rest of the terminal area.